Oberwolfach/gyro_m graph

Matrix: Oberwolfach/gyro_m

Description: Oberwolfach: butterfly gyro, M matrix


  • UF Sparse Matrix Collection
  • Matrix group: Oberwolfach
  • Click here for a description of the Oberwolfach group.
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  • download as a MATLAB mat-file, file size: 1 MB. Use UFget(1203) or UFget('Oberwolfach/gyro_m') in MATLAB.
  • download in Matrix Market format
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    Oberwolfach/gyro_m

    dmperm of Oberwolfach/gyro_m

    Matrix properties
    number of rows17,361
    number of columns17,361
    nonzeros340,431
    structural full rank?yes
    structural rank17,361
    # of blocks from dmperm3
    # strongly connected comp.3
    entries not in dmperm blocks0
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typereal
    structuresymmetric
    Cholesky candidate?yes
    positive definite?yes

    authorD. Billger
    editorE. Rudnyi
    date2004
    kindduplicate model reduction problem
    2D/3D problem?yes

    Ordering statistics:AMD METIS DMPERM+
    nnz(chol(P*(A+A'+s*I)*P'))416,577 526,165 416,577
    Cholesky flop count1.4e+07 2.3e+07 1.4e+07
    nnz(L+U), no partial pivoting815,793 1,034,969 815,793
    nnz(V) for QR, upper bound nnz(L) for LU790,960 925,965 675,816
    nnz(R) for QR, upper bound nnz(U) for LU2,079,132 2,241,193 1,626,534

    Maintained by Tim Davis, last updated 30-Sep-2008.
    Matrix pictures by cspy, a MATLAB function in the CSparse package.
    Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.